Agitator



Patented July 1.3, 1937 ,UNITED STATES aGITAiroR Joseph E. Bond, Middletown, Ohio Application April 4, 1935, Serial No. 14,671

8 Claims.

This invention relates to the' art of paper making, and more'particularly to means for -agitating paper pulp andthe like. f

One object of the invention is the provision of an agitator for paper pulp stock or the like, and comprising' a tank having a pump adapted to withdraw the stock from a low point of the tank and to return the stock at a higher point, the tank having baille walls so arranged as to provide effective intermixing andthorough agitation of the masses which circulate in the tank.

Another object of the invention is the provision of a stock agitating tank in which the stock is adapted to circulate from one point to another,

an inclined baille wall being provided so as to coniine the stock in its passage towards the pump inlet so that foamy stock or stock that is not ,thoroughly de-aerated is carried along to the pump inlet with the other portions of the stock. Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing .and the appended claims, in which,- y

Fig. 1 is a top plan view of an agitator embodying the present invention;

Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1; and

Fig. 3 is a section taken transversely through the tank on the line 3-3 of Fig. 2.

Referring more particularly to the drawing by reference numerals, I0 generally designates a tank of suitable dimensions adapted to hold a batch of paper stock or the like. ,The stock is adapted to be circulated in the tank Il),y which is 35 provided with a baille wall Il shown in the form of a midfeather which terminates some distance from the tank ends. lAt one side of the mid` feather or wall Il is a side passage l2, having aninclined floor I3 down which the stock passes 40 under the action of gravity. The stock then flows around the end of the midfeather and then along the side passage I4 which is arranged on the other side of the midfeather Il.

' The stock is withdrawn from a low point of the 45 tank by means of a pipe or passage I6 which extends to the inlet side of a motor driven pump I1 which is of such character as to produce a suitable suction on its inlet side and deliverthe stock under suitable head at its outlet side. Thepump 50 outlet is connected by means of a pipe I8 toA a point 1n the tank Isomewhat higher than the pump inlet, as apparent from Fig. 2.

As will `be noted from Fig. '-2, above lone end of the side passage Il is an inclined baille wall 20 up 55 which the stock passes after owing out of the pump` discharge passage I8, the pump outlet being `connected to a point above the wall 20 while the pump inlet is connected to a point below that wall. Above the wall 2D is another inclined baille wall 2l so that the stock is somewhat conned in 5 its passage between the two walls 20 and 2l until it reaches the upper level of the wall 2i, over which it flows. It then Apasses down along theupper side of the wall 2| in moving through the passage 23 which is in communication with the 10 right-hand end of the side passage l2, as shown in Fig. 1. The stock received by the tank is, therefore, forced by the pressure exerted by pump I1 to a high enough level determined by the top of the baille wall 2| so that it will flow by gravity 15 around the midfeather and into the inlet side ofv the pump to be again returned and recirculated.

The wall 20 is provided with a suitable opening or openings so that some portion of the stock which passes upwardly above it is promptly re- 20 turned as a fall or auxiliary circuit to apoint comparatively close to the pump inlet. As shown,

a plurality of holes 24 are provided for this purpose near the upper end of the wall 20. In the` circulation of certain gradesof stock diiiiculties 25` have been encounteredin its agitation owing to foamy stock or to stock that is not thoroughly de-aerated. Such stock tends to float and accumulate over a suction opening and where the suction is some distance from the upper level of 30 the` stock the floating or foamy portion is not circulated with the other portions of the stock. The baille wall 20, however, prevents this accumulation of the foamy or other light stock portions, as it is inclined ata considerable angle and as the fall of stock through the openings 24 provides a submerging stream that breaks up any foam that happens to be present and which might tend to float even against this angle of the baille. The stock is, therefore, thoroughly intermixed and the lighter portions are carried along with the main body of the stock.

The openings 24 inA the baille wall 20 provide for the passage of a limited amount of stock in a comparatively short circuit between the pump outlet and the pump inlet while the main portion of the stock passes through the comparatively long circuit around the midfeather Il. This auxiliary ow through the openings 24 is effective not onlylinbreaking up any foam that might be present in the stock on the under side of the wall 20 but also in intimately mixing difl ferent bodies of the stock together. For bleaching and for mixing of colors and similar operations a more perfect blending action is provided because some of the stock passes quickly through the circulating tank while other portions flowing into the tank at the same time :equire a longer time in completing its circuit. i

This intermlxing is also facilitated by an additional oriiice or passage shown in the form of a hole 26 provided in the inclined baille Wall 2| at a pointcomparatively remote from the end of the midfeather and in a corner portion of the tank. The pump inlet I8 is at some distance from this corner of the tank, but any tendency for the stock to accumulate in that corner is overcome by reason of the iiow produced upwardly through the hole 26 so that the stock in the corner is kept moving. The stock whichf passes through the hole 26 then ows across the upper side of the wall 2|, thus breaking up any stock which would otherwise tend to accumulate immediately above the wall 2| adjacent the side wall of the tank. This cross flow above the wall 2| is represented by the arrow 21 in Fig. 1. The hole 26 supplements the action of the openings 24 in giving a thorough intermxing action and provides a diierent length of circuit for a restricted portion of the pulp by reason of its passage through the hole 26 instead of moving up along the under side of the wall 2| with the main portion of the stock. Different bodies of the "stock therefore have different periods of time required in moving from the pump outlet back to the inlet through the tank so that a. certain portion comes back almost immediately while another portion passes through the orifice 26 and the main portion moves up over the wall 20 and then flows over the top of the wall 2| and then around the midfeather.

The stock is withdrawn, as desired, from the stock chest orjtank by means of the discharge pipe 28 after thorough mixing and agitation, or after the desired coloring or bleaching operation has been effected, and additional stock is supplied through the illling passage 29. Y

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and

, that changes may be made therein without departing from the scope of` the invention which is deiined in the appended claims.

What is claimed is:

1. A stock agitator for mixing stock comprising a tank, a pump for circulating stock in the tankZ said tank having a midfeather providing for circulating flow of the main body oi stock in a comparatively long path from the pump outletback to the pump inlet, and a pair of spaced baille walls arranged `one above the other and both inclined at alarge angle to the vertical, the upper wall coniining therebelow the stock flowing from the pump outlet and the lower wall confining therebelow the stock flowing to the vpump inlet, said walls each having provision for bypassing portions of the stock at diierent points along said path in shorter paths in circulating from the pump outlet to the pump inlet.

\ circulating from the pump outlet to the pump the other and inclined downwardly at an angle of the order of 45. to the vertical, one of said baille walls being inclined downwardly toward the pump inlet and confining the stock therebelow in its movement to the pump inlet.

3. In an agitator for mixing stock, a circulating tank, a pump for circulating stock in the tank from a low point therein, a baille wall in said tank around which the main body of stock circulates in moving from the pump outlet to the pump inlet, said baiile wall inclining downwardly toward the pump inlet and conning the stock -therebelow in moving to the pump inlet, said baille wall having means for-bypassing a stream of stock onto the main body of circulating stock, and a second baille wall around which the main body of stock circulates extending from an end wall of the tank and provided substantially parallel to and above the iirst mentioned baille wall and conining the stock received from the pump outlet on its lower side.

4. In an agitator for mixing stock, a circulating tank, a pump for circulating stock in the tank from a low point therein, a baille wall in said tank around which the main body of stock circulates in moving from the pump outlet to the pump inlet, said baille wall inclining downwardly toward the pump inlet and conning the stock therebelow in moving to the pump inlet, said baffle wall having means for. bypassing a stream of stock onto the main body of circulating stock, and a second baille wall around which the main body of stock circulates and provided above the rst mentioned baille wall and coniining the stock received from the pump outlet on its lower side, said second baille wall having means at a distance from the pump outlet but adjacent the bottom of the wall for bypassing a portion of the stockv from the main body of stock.

5. 'An agitator for mixing paper stock comprising a tank, a pump having its inlet connected to a low point in said tank and adapted for circulating the stock in the tank upper and lower baille walls both inclined downwardly at an an'- gle of the order of 45 toward the pump inlet and confining the stock therebetween, the lower baille wall extending below the pump outlet and confining the stock on its lower side in its movement to the pump inlet and having means for bypassing a portion of the stock received from the pump outlet for prompt return to the pump inlet.

6. An agitator for mixing paper stock comprising a tank, a pump having its inlet connected to a low point insaid tank and adapted for circulating the stock in the tank, upper and lower bame walls inclined downwardly .toward the pump inlet and confining the stock received from the pump outlet therebetween, the lower baille wall confining the stock on its lower side in its movement to the pump inlet and having means f for bypassing a portion of the stock received from the pump outlet for prompt return to 'the Apump inlet, said upper baille wall having a passage adjacent the end of the tank and' at a remote corner portion of the stock passage providing a restricted iiow from a point adjacent the pump outlet to a point above said upper baille w'all for the agitation of the stock in the corner portion. y i

7. An agitator for mixing paper'stock comprising a tank having a rnidi'eatherl wall terminating at a distance from opposite ends of the tank and providing opposed side passages for the stock, a 75 pump havmgits inlet connected to a low point "of the tank at one side of said midfeather, an inwall; a second baiile`wa1l inclined ata large angle to the vertical over which the main portion of 10 the stock flows to a side passage and provided above said first baille wall, said second bafiie wall having an opening near its bottom portion'providing for a restricted bypass ilow of stock from a point spaced from the pump voutletl and adja- 15 cent a wall of the tank.

8. A stock agitator for mixing stock comprising a tank, a pump for circulating the stock in the tank and having its inlet connected to a low point in the tank, said tank having a division wall around which the stock circulates from the pump outlet to the pump inlet and having an inclinedl bailie wall extending angularly downwardly at one side of the division wall toward and above the pump inlet and conning the stock therebelow as the stock passes to the pump inlet, and a second baille wall over which the stock ilows to the main circulating body of stock and extending downwardly above the first wall at an angle of the order of 45 inclination and conning therebelow the stock flowing from the pump outlet, said second baille wall having an opening at a distance from the pump outlet but near the bottom of said wall and providing an upward flow through the said wall;

JOSEPH E. BOND. 

